Suspension-bridge.



PATENTED FEB. '7, 1905.

W. HILDENBRAND. SUSPENSION BRIDGE.

APPLICATION nun mm. 27. 1900.

571- uc I do 3 MW 351 @Hozucu I UNITED STATES Patented February '7,1905.

VILHELM HILDENBRAND, OF NETV YORK, N. Y.

SUSPENSION-BRIDGE.

SPECIFICATION forming part of Letters Patent No. 782,027, dated February7, 1905,

Application filed February 27, 1900. Serial No. 6,731.

To all whom it may concern:

Be it known that LVILHELM HILDENBRAND, a citizen of the United States,and a resident of New York city, in the county of New York and State ofNew York, have invented a certain new and useful Improvement inSuspension-Bridges, of which the following-is aspccification.

The present invention relates to improvements in suspension-bridges, oneobject being to render the construction thereof less hazardous thanheretofore.

Another object is to reduce the strains upon the letting-off apparatus.

Another object is to be able to lengthen strands as well as to shortenthem.

Another object of the invention is to be able to vary the length ofstrands without removing the pins by which they are secured to the upperends of the anchor-bars and other objects, as will hereinafter appear.

To these ends the invention consists of features of construction andcombinations of devices hereinafter described, and more particularlypointed out in the appended claims.

In constructing cables for suspensionbridges of large span the strandsare not built in their final positions; but the shoes for the ends ofeach strand are fastened to temporary bars and pins placed somewhat backfrom the linal positions of the shoes, and after the strand is completeda suitable apparatus takes hold of each shoe, releases it from itstemporary seat, and moves it that is, lets off the strand to its finalposition between two anchor-bars, where it is pinned.

in a prior method of attaching wire cables to anchor-bars there havebeen employed two such bars for each end of each of the strands makingup the cable, the eyes of the strands being formed about metal shoeswhich are held between the anchor-bars by round pins, which lit roundholes in the bars and abut against a semicylindrical end surface ofoblong or elongated perforation or through-slots in the shoes or againstsegments or liners, which rest against said end surfaces. If when saidend surfaces of the shoes rest against the pins the strand is not longenough, there is no I way of lengthening it so that it can be used 5without changing the design of the entire bridge, though a strand whichis too long may be shortened by pulling back the shoe and strand,drawing out the pin, lifting the shoe out, and placing one or more steelsegments of suitable thickness against said end surface of the slot inthe shoe, and then replacing the strand and shoe between the anchor-barsand replacing the pin. It is obvious that the pin must be removed fromthe slot in the shoe before the shoe can be taken out for the insertionof the liner segment or segments. This removal of the pin, the shoe, andthe strand end is troublesome, laborious, and dangerous, since thestrand must be held meanwhile against very great tension, sometimes asmuch as seventy (70) tons, and the operation becomes more troublesome,laborious, and dangerous when, as in another prior construction, one pinserves to retain several strands. In the latter case thereare more eyeor anchor bars by one than there are strands, so that each strand liesbetween two'such eye-bars and the pin passes through all the bars andstrandshoes. in the last-named case it may be requisite that two or moreof the strands shall be held temporarily while the pin is drawn ordriven out and the required strand shoe lifted out and the segments orsegment inserted and also while these parts are being replaced.

According to the present invention each main strand is divided, bypreference, into three substrands, and one end of each of thesesubstrands is placed on a shoe between two eye-bars, and the ends ofeach of the other two substrands are placed on shoes which are mountedon extensions of the (single) pins by which each of the first-namedshoes is secured to the eye-bars. The substrands are regulatedseparately in any suitable or known manner, the middle substrandthatbetween the eyebars-bcing regulated first and the other two beingregulated afterward without removal of the pin from its position, saidsubstrands being put in place by slipping their shoes over theprojecting ends or extensions of the pins by which the shoes .for themiddle substrand are held in place. In any given bridge the number andsize of the eye or anchor bars and the diameters of the pins do not inthe new construction of the strands vary from what they would he wereprior methods used; but the pins are longer in order to provide supportsfor the outside shoes. With the new construction and arrangement theletting-0E apparatus need be only about one-third as strong as it mustbe in the case where the larger strand is to be let off, thus making itsconstruction simpler, rendering it capable of being operatedby hand, andreducing the dangers, especially since the loads are reduced abouttwo-thirds. After being regulated the substrands are wrapped or clampedtogether to form a main strand, and the various main strands aresubsequently formed into a circular or circularly-shaped cable in anysuitable or known manner.

One part of my invention makes provision for the regulation of a strandafter it is in place between two eye or anchor bars without thenecessity of removing or disturbing the pin by which the shoe isfastened to the eyes. One or both of the eye-bars for each main strandis provided with an oblong or elongated perforation or through-slothaving a round or semicylindrical end to form a seat for the said pin,said perforation or slot being of a size such that the segments orliners aforesaid may be inserted and removed therethrough, so that thesegment or liner may be put in place between the shoe and the pin andalso be removed therethrough Without the pin being moved or displacedfrom its working positionthat is, the regulating can be done in perfectsafety without disengaging the shoe and the pin from each other, sinceshould the letting-off apparatus fail the shoe can only move relativelyto the pin by the distance separating said rounded end of the shoe-slotfrom the pin.

For the purpose of lengthening as well as shortening a strandmain orsub, as the case may be l provide'the usual slot in the shoes with anumber of liners or segments, which are detachably secured in place inthe slot. These segments are to be in place in the shoe when the strandis built and let off. These segments may be held in place in the slot inany convenient manner, as by magnetizing one or more of themsufliciently to prevent them from falling out before the shoe bearsagainst the pin, or rather before the inner segment bears against thepin, or the segments may be held in place by mechanical means.

In order to secure uniformity of size in a suspension-bridge cable andto render the wire forming the same equally flexible at all points, theends of the separate wires making up the strand are united by brazing orsoldering or by welding. The brazed or welded joint or union ispractically of the same diameter as the wires and is equally flexible.In this Way the inflexibility of prior unions or splices of the wires insuspension-bridge work is altogether avoided and a construction by whichthe union may pass around the small sheaves and other sharp curveswithout danger of breaking the union is provided. When the priorsplices, as right and left threads on the abutting or adjacent ends oftwo wires and a right and left threaded sleeve-nut, a

telegraph-wire splice, and tapered or scarfed joints and wire-wrappingthereon, come at such sharply-curved places, the splices must be cut andremade in order to transfer the splice to a straight portion of thestrand; but the new unions may come at the bights or eyes of the strandsand may pass around sheaves without danger of being broken. Oneadvantage of the new union is that the cables and strands are of uniformsize throughout, the humps and inequalities due to the prior splicesbeing wholly eliminated. Also each wire is of uniform section and ofequal flexibility throughout.

The invention is illustrated in the accompanying drawings, forming partof this specification, in which- Figure 1 is a plan view of anembodiment of my new method of forming strands and attaching them toanchor-bars. Fig. 1" is a like view of a prior method of making andattaching strands to anchor-bars. Fig. 2 is a side elevation of theconstruction shown in Fig. 1. Fig. 2 is a like View of the constructionshown in Fig. 1. Fig. 3 is a crosssection of a cable wherein the mainstrands are each composed of three substrands. Fig. 3 is across-sectional view of an ordinary cable having a number of strandsequal in number to the main strands shown in Fig. 3. Fig. l is a sideelevation, and Fig. 5 is a horizontal section, of a shoe and segmentsdetachably connected thereto.

The same reference character will be employed to designate the same partin the different figures of the drawings.

2 indicates the upper ends of anchor-bars, to which the cable-strandsare connected.

3 is a round pin or bar which fits in round holes in the bars 2 in theold construction, Figs. 1 and 2, and against the semicylindrical end ofthe through-slots 4 in the new construction of the anchor-bars.

5 represents metal strand-shoes or castings, each having the usualthrough-slot 6, provided with semicylindrical seats 7 to fit on the pins3.

8 is the old strand, made up of straight parallel wires having eyes orbights therein to pass around the shoes 5, and 9 is the new main strand,made up of three substrands 1O 11 12. The substrands 1O 11 12 are formedwith bights or eyes 13, which'go over the shoes 5.

In Figs. 1 and 2 he pin 3 extends through and beyond both of the bars 2and three shoes 5 are mounted thereon, one of these shoes being placedon the pin between the eyes of the bars 2 and the other two shoes beingmounted on the projecting'ends of said pin. The eyes 13 of thesubstrands 10 and 12 are on the shoes 5, which are outside of the bars2. while the bight of strand 11 is on the shoe which is between the eyesof bars 2.

1-1 indicates a liner or segment between the pin 3 and seat 7 of a shoe5. By removing said segment 11 the strand may be lengthened, thusincreasing the sag thereof between its points of suspension. Thesubstrands are clamped or wrapped temporarily or permanently to form amain strand, and all the main strands are brought together to form acylindrically-shaped cable, which is then suitably covered.

Referring to Figs. 1 and 5, the shoe 5 is shown as provided with grooves15 therein, parallel with the slot 6, and with bars 16, secured in saidgrooves by countersunk screws 17. The bars 16 extend partly across theslot 6 and embrace a number of segments or liners 14, which are notchedat their ends to receive said bars 16. Small countersunk screws 18 serveto attach segments 14 to the bars 16 and hold the segments in place,abutting against the end face 7 of the slot 6. The describedconstruction provides a means whereby the shoes and segments may betransported together and the strands be built up on the shoes while thesegments are in place in the slots 6. The bars 16 may be nicked at eachjoint between segments, as indicated by the heavy lines, and also at thejoint between the end segment and the end of the slot 6 in the shoe 5,so that they may be broken OH with a chisel and hammer or the like whendesired.

The strand or substrand is built around the shoe 5 in the usual mannerand is let off in any usual way and the shoe pinned to its eyebars 2 inits permanent position, the segments 11 being still in place in theshoe. If now the strand or substrand is too short, the strain is takenoff the pin and the requisite number of segments removed. Thus if thestrand or substrand is one-half inch too short and each segment 11 isone-quarter of an inch thick the adjustment is made by removing thescrews 18 from the two inner segments 14 or those next the pin andbreaking the bars 16 at the joint between the fourth and fifth segments,counting from the end face 7 of the slot 6. If the said shoe andsegments be between anchor-bars which embody my present in provementtherein, the above-described operation is carried out through the slotset without moving the pin 3 in any manner, the segments removed beingtaken out through the said slots 1 or one of them. On letting off thestrand the fourth segment from face 7 now comes against the pin 3, andthe strand (or substrand) in the case assumed is lengthened by one-halfinch, or the strand may be shortened by inserting one or more segmentsthrough a slot or slots 1, all without removing or disturbing pin 3.

\Vhile I have described the preferred form of my invention, .I do notlimit myself to the precise form thereof shown in the drawings andhereinbefore described, inasmuch as the invention may be embodied inmany forms without departing from the scope of the claims herein.

Having thus fully and clearly described my invention, what I claim asnew, and desire to secure by Letters Patent of the United States, is?

1. In a suspension-bridge, a main strand consisting of three substrands,combined with two pairs of anchor-bars, and pins in said anchor-barsextending outside said bars on which pins the eyes of the substrands areall secured between and outside said pairs of bars.

2. A strand-shoe for a suspension-bridge provided with a number ofsegments detachably connected thereto and placed at one end of the slottherethrough.

3. A main strand for suspension-bridge cables consisting of threesubstrands each formed of a bundle of wires said substrands being unitedto form the main strand, a pair of anchor-bars at each end of said mainstrand, a pin for and extending through each pair of anchor-bars, andshoes for each substrand, the shoes for one substrand being between themembers of said pairs of bars and the other shoes being outside of saidbars, all in combination.

I. In a suspension-bridge, the combination of the two anchor-bars atleast one of which is provided with an oblong perforation orthrough-slot, a strand-shoe, a segment, and a pin connecting said shoeand bars, and passing through said slot, whereby the segment may beinserted through said slot and placed between said pin and shoe and beremoved without unpinning said shoe and thereby regulating or varyingthe length of the strand held by said shoe pin and bars, substantiallyas described.

5. In a suspension-bridge, the combination of two anchor-bars, a pinextending through and outside of each of said bars, a strand-shoe onsaid pin between said bars, strand-shoes on the projecting ends of saidpin, and strands on said shoes, substantially as described.

6. In a suspension-bridge, the combination of two anchor-bars, a pinextending through and outside of each bar, at least one of said barsbeing provided with an oblong perforation or through-slot in which saidpin rests at one end of the slot, a strand-shoe on said pin between saidbars, strand-shoes on said pin outside of said bars, and strands on saidshoes,

Signed at New York city, in the county of New York and State of NewYork, this 26th whereby segments for varying the length of dayofFebruary, A. D. 1900. the strand 0n the middle shoe may be inserted andremoved through said slot in said bar Without unpinning the said middleshoe, substantially as described.

VVILHELM HILDENBRAND. i/Vitnesses:

RICHARD WV. BARKLEY, Gus. E. HENNING.

